qemu: enforce maximum ports value for nec-xhci

This controller only allows up to 15 ports.

https://bugzilla.redhat.com/show_bug.cgi?id=1375417

src/qemu/qemu_domain.c

@@ -3005,6 +3005,9 @@ qemuDomainShmemDefPostParse(virDomainShmemDefPtr shm)
 }
 
 
+#define QEMU_USB_NEC_XHCI_MAXPORTS 15
+
+
 static int
 qemuDomainDeviceDefPostParse(virDomainDeviceDefPtr dev,
                              const virDomainDef *def,
@@ -3159,6 +3162,15 @@ qemuDomainDeviceDefPostParse(virDomainDeviceDefPtr dev,
     if (dev->type == VIR_DOMAIN_DEVICE_CONTROLLER) {
         virDomainControllerDefPtr cont = dev->data.controller;
 
+        if (cont->type == VIR_DOMAIN_CONTROLLER_TYPE_USB &&
+            cont->model == VIR_DOMAIN_CONTROLLER_MODEL_USB_NEC_XHCI &&
+            cont->opts.usbopts.ports > QEMU_USB_NEC_XHCI_MAXPORTS) {
+            virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                           _("nec-xhci controller only supports up to %u ports"),
+                           QEMU_USB_NEC_XHCI_MAXPORTS);
+            goto cleanup;
+        }
+
         if (cont->type == VIR_DOMAIN_CONTROLLER_TYPE_PCI) {
             if (cont->model == VIR_DOMAIN_CONTROLLER_MODEL_PCI_EXPANDER_BUS &&
                 !qemuDomainMachineIsI440FX(def)) {

tests/qemuxml2argvdata/qemuxml2argv-usb-controller-xhci-limit.xml

+<domain type='qemu'>
+  <name>QEMUGuest1</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <memory unit='KiB'>219136</memory>
+  <currentMemory unit='KiB'>219136</currentMemory>
+  <vcpu placement='static'>1</vcpu>
+  <os>
+    <type arch='i686' machine='pc'>hvm</type>
+    <boot dev='hd'/>
+  </os>
+  <devices>
+    <emulator>/usr/bin/qemu</emulator>
+    <controller type='usb' index='0' model='nec-xhci' ports='16'/>
+    <memballoon model='none'/>
+  </devices>
+</domain>

tests/qemuxml2argvtest.c

@@ -1418,6 +1418,9 @@ mymain(void)
             QEMU_CAPS_CHARDEV, QEMU_CAPS_NODEFCONFIG, QEMU_CAPS_PIIX3_USB_UHCI,
             QEMU_CAPS_NEC_USB_XHCI, QEMU_CAPS_NEC_USB_XHCI_PORTS,
             QEMU_CAPS_USB_HUB);
+    DO_TEST_PARSE_ERROR("usb-controller-xhci-limit",
+            QEMU_CAPS_CHARDEV, QEMU_CAPS_NODEFCONFIG, QEMU_CAPS_PIIX3_USB_UHCI,
+            QEMU_CAPS_NEC_USB_XHCI, QEMU_CAPS_NEC_USB_XHCI_PORTS);
 
     DO_TEST("smbios", QEMU_CAPS_SMBIOS_TYPE);
     DO_TEST_PARSE_ERROR("smbios-date", QEMU_CAPS_SMBIOS_TYPE);